include/linux/cpufreq.h

   1 /*
   2  *  linux/include/linux/cpufreq.h
   3  *
   4  *  Copyright (C) 2001 Russell King
   5  *            (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
   6  *
   7  *
   8  * $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db Exp $
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14 #ifndef _LINUX_CPUFREQ_H
  15 #define _LINUX_CPUFREQ_H
  16
  17 #include <linux/mutex.h>
  18 #include <linux/notifier.h>
  19 #include <linux/threads.h>
  20 #include <linux/device.h>
  21 #include <linux/kobject.h>
  22 #include <linux/sysfs.h>
  23 #include <linux/completion.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/cpumask.h>
  26 #include <asm/div64.h>
  27
  28 #define CPUFREQ_NAME_LEN 16
  29
  30
  31 /*********************************************************************
  32  *                     CPUFREQ NOTIFIER INTERFACE                    *
  33  *********************************************************************/
  34
  35 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
  36 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
  37
  38 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
  39 #define CPUFREQ_POLICY_NOTIFIER         (1)
  40
  41
  42 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
  43  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
  44  * two generic policies are available:
  45  */
  46
  47 #define CPUFREQ_POLICY_POWERSAVE        (1)
  48 #define CPUFREQ_POLICY_PERFORMANCE      (2)
  49
  50 /* Frequency values here are CPU kHz so that hardware which doesn't run
  51  * with some frequencies can complain without having to guess what per
  52  * cent / per mille means.
  53  * Maximum transition latency is in nanoseconds - if it's unknown,
  54  * CPUFREQ_ETERNAL shall be used.
  55  */
  56
  57 struct cpufreq_governor;
  58
  59 #define CPUFREQ_ETERNAL                 (-1)
  60 struct cpufreq_cpuinfo {
  61         unsigned int            max_freq;
  62         unsigned int            min_freq;
  63         unsigned int            transition_latency; /* in 10^(-9) s = nanoseconds */
  64 };
  65
  66 struct cpufreq_real_policy {
  67         unsigned int            min;    /* in kHz */
  68         unsigned int            max;    /* in kHz */
  69         unsigned int            policy; /* see above */
  70         struct cpufreq_governor *governor; /* see below */
  71 };
  72
  73 struct cpufreq_policy {
  74         cpumask_t               cpus;   /* affected CPUs */
  75         unsigned int            shared_type; /* ANY or ALL affected CPUs
  76                                                 should set cpufreq */
  77         unsigned int            cpu;    /* cpu nr of registered CPU */
  78         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  79
  80         unsigned int            min;    /* in kHz */
  81         unsigned int            max;    /* in kHz */
  82         unsigned int            cur;    /* in kHz, only needed if cpufreq
  83                                          * governors are used */
  84         unsigned int            policy; /* see above */
  85         struct cpufreq_governor *governor; /* see below */
  86
  87         struct work_struct      update; /* if update_policy() needs to be
  88                                          * called, but you're in IRQ context */
  89
  90         struct cpufreq_real_policy      user_policy;
  91
  92         struct kobject          kobj;
  93         struct completion       kobj_unregister;
  94 };
  95
  96 #define CPUFREQ_ADJUST          (0)
  97 #define CPUFREQ_INCOMPATIBLE    (1)
  98 #define CPUFREQ_NOTIFY          (2)
  99
 100 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 101 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 102 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 103 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 104
 105 /******************** cpufreq transition notifiers *******************/
 106
 107 #define CPUFREQ_PRECHANGE       (0)
 108 #define CPUFREQ_POSTCHANGE      (1)
 109 #define CPUFREQ_RESUMECHANGE    (8)
 110 #define CPUFREQ_SUSPENDCHANGE   (9)
 111
 112 struct cpufreq_freqs {
 113         unsigned int cpu;       /* cpu nr */
 114         unsigned int old;
 115         unsigned int new;
 116         u8 flags;               /* flags of cpufreq_driver, see below. */
 117 };
 118
 119
 120 /**
 121  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 122  * @old:   old value
 123  * @div:   divisor
 124  * @mult:  multiplier
 125  *
 126  *
 127  *    new = old * mult / div
 128  */
 129 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 130 {
 131 #if BITS_PER_LONG == 32
 132
 133         u64 result = ((u64) old) * ((u64) mult);
 134         do_div(result, div);
 135         return (unsigned long) result;
 136
 137 #elif BITS_PER_LONG == 64
 138
 139         unsigned long result = old * ((u64) mult);
 140         result /= div;
 141         return result;
 142
 143 #endif
 144 };
 145
 146 /*********************************************************************
 147  *                          CPUFREQ GOVERNORS                        *
 148  *********************************************************************/
 149
 150 #define CPUFREQ_GOV_START  1
 151 #define CPUFREQ_GOV_STOP   2
 152 #define CPUFREQ_GOV_LIMITS 3
 153
 154 struct cpufreq_governor {
 155         char    name[CPUFREQ_NAME_LEN];
 156         int     (*governor)     (struct cpufreq_policy *policy,
 157                                  unsigned int event);
 158         unsigned int max_transition_latency; /* HW must be able to switch to
 159                         next freq faster than this value in nano secs or we
 160                         will fallback to performance governor */
 161         struct list_head        governor_list;
 162         struct module           *owner;
 163 };
 164
 165 /* pass a target to the cpufreq driver
 166  */
 167 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 168                                  unsigned int target_freq,
 169                                  unsigned int relation);
 170 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 171                                    unsigned int target_freq,
 172                                    unsigned int relation);
 173
 174
 175 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy);
 176
 177 int cpufreq_register_governor(struct cpufreq_governor *governor);
 178 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 179
 180 int lock_policy_rwsem_read(int cpu);
 181 int lock_policy_rwsem_write(int cpu);
 182 void unlock_policy_rwsem_read(int cpu);
 183 void unlock_policy_rwsem_write(int cpu);
 184
 185
 186 /*********************************************************************
 187  *                      CPUFREQ DRIVER INTERFACE                     *
 188  *********************************************************************/
 189
 190 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 191 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 192
 193 struct freq_attr;
 194
 195 struct cpufreq_driver {
 196         struct module           *owner;
 197         char                    name[CPUFREQ_NAME_LEN];
 198         u8                      flags;
 199
 200         /* needed by all drivers */
 201         int     (*init)         (struct cpufreq_policy *policy);
 202         int     (*verify)       (struct cpufreq_policy *policy);
 203
 204         /* define one out of two */
 205         int     (*setpolicy)    (struct cpufreq_policy *policy);
 206         int     (*target)       (struct cpufreq_policy *policy,
 207                                  unsigned int target_freq,
 208                                  unsigned int relation);
 209
 210         /* should be defined, if possible */
 211         unsigned int    (*get)  (unsigned int cpu);
 212
 213         /* optional */
 214         unsigned int (*getavg)  (unsigned int cpu);
 215         int     (*exit)         (struct cpufreq_policy *policy);
 216         int     (*suspend)      (struct cpufreq_policy *policy, pm_message_t pmsg);
 217         int     (*resume)       (struct cpufreq_policy *policy);
 218         struct freq_attr        **attr;
 219 };
 220
 221 /* flags */
 222
 223 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 224                                          * all ->init() calls failed */
 225 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 226                                          * "constants" aren't affected by
 227                                          * frequency transitions */
 228 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 229                                          * mismatches */
 230
 231 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 232 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 233
 234
 235 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 236
 237
 238 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 239 {
 240         if (policy->min < min)
 241                 policy->min = min;
 242         if (policy->max < min)
 243                 policy->max = min;
 244         if (policy->min > max)
 245                 policy->min = max;
 246         if (policy->max > max)
 247                 policy->max = max;
 248         if (policy->min > policy->max)
 249                 policy->min = policy->max;
 250         return;
 251 }
 252
 253 struct freq_attr {
 254         struct attribute attr;
 255         ssize_t (*show)(struct cpufreq_policy *, char *);
 256         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 257 };
 258
 259
 260 /*********************************************************************
 261  *                        CPUFREQ 2.6. INTERFACE                     *
 262  *********************************************************************/
 263 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 264 int cpufreq_update_policy(unsigned int cpu);
 265
 266 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 267 unsigned int cpufreq_get(unsigned int cpu);
 268
 269 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 270 #ifdef CONFIG_CPU_FREQ
 271 unsigned int cpufreq_quick_get(unsigned int cpu);
 272 #else
 273 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 274 {
 275         return 0;
 276 }
 277 #endif
 278
 279
 280 /*********************************************************************
 281  *                       CPUFREQ DEFAULT GOVERNOR                    *
 282  *********************************************************************/
 283
 284
 285 /*
 286   Performance governor is fallback governor if any other gov failed to
 287   auto load due latency restrictions
 288 */
 289 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 290 extern struct cpufreq_governor cpufreq_gov_performance;
 291 #endif
 292 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 293 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 294 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 295 extern struct cpufreq_governor cpufreq_gov_userspace;
 296 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 297 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 298 extern struct cpufreq_governor cpufreq_gov_ondemand;
 299 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 300 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 301 extern struct cpufreq_governor cpufreq_gov_conservative;
 302 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 303 #endif
 304
 305
 306 /*********************************************************************
 307  *                     FREQUENCY TABLE HELPERS                       *
 308  *********************************************************************/
 309
 310 #define CPUFREQ_ENTRY_INVALID ~0
 311 #define CPUFREQ_TABLE_END     ~1
 312
 313 struct cpufreq_frequency_table {
 314         unsigned int    index;     /* any */
 315         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 316                                     * order */
 317 };
 318
 319 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 320                                     struct cpufreq_frequency_table *table);
 321
 322 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 323                                    struct cpufreq_frequency_table *table);
 324
 325 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 326                                    struct cpufreq_frequency_table *table,
 327                                    unsigned int target_freq,
 328                                    unsigned int relation,
 329                                    unsigned int *index);
 330
 331 /* the following 3 funtions are for cpufreq core use only */
 332 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 333 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 334 void   cpufreq_cpu_put (struct cpufreq_policy *data);
 335
 336 /* the following are really really optional */
 337 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 338
 339 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 340                                       unsigned int cpu);
 341
 342 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 343
 344
 345 /*********************************************************************
 346  *                     UNIFIED DEBUG HELPERS                         *
 347  *********************************************************************/
 348
 349 #define CPUFREQ_DEBUG_CORE      1
 350 #define CPUFREQ_DEBUG_DRIVER    2
 351 #define CPUFREQ_DEBUG_GOVERNOR  4
 352
 353 #ifdef CONFIG_CPU_FREQ_DEBUG
 354
 355 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
 356                                  const char *fmt, ...);
 357
 358 #else
 359
 360 #define cpufreq_debug_printk(msg...) do { } while(0)
 361
 362 #endif /* CONFIG_CPU_FREQ_DEBUG */
 363
 364 #endif /* _LINUX_CPUFREQ_H */